Hydraulic elevator.



No. 668,238. Patented Feb. I9, |9ol.

J. E. wAlT.

HYDRAULIC ELEVATOR.l (Application led. Mar. 19, 1900.)

(No Model.)

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`JACOB E. WAIT, OF DETROIT, MICHIGAN HYDRAULIC VELEVATOR.. l,

SEEGIFICATION forming part of Letters Patent N o. 668,238, dated February 19, 1901.l Application liled March 19, 1900. Serial No. 9,305. (No model.)

To all whom, .it may concern:

Be it known that l, JACOB E. WAIT, a citizen of the United States, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Hydraulic Elevators, of which the following is a specification, reference being had therein to the accompanying drawing.

The invention has generai reference to elevators, and relates particularly to that type known as hydraulic elevators.

The principal object of the invention is to providea counter-balance for the car in theform a hydrostatic column and to so. arrange and combine the column with the hydraulic liftingr mechanism that the former will counterbalance the car at every point of its travel. l

.Another object of equal importance is to construct the column in such manner that in addition to performing the function as above set 'forth it will constantly counterbalance the dead-weight of the cable, varying in hydrostatic pressure to compensate for the variance of the deadwveight caused by the movement of the car.

With these principal objects in view my invention consists in the novel construction of acounterbalance and in the peculiar construction, arrangement, and combination of various other parte of the elevator mechanism, as will be hereinafter described, and shown lin the drawing, in which the flgureis a sectional elevation of the hydraulic lifting mechanism, showing the car in diagram.

' The reference-letter A designates the cylinder of usual l'orm mounted upon supports, such as B, and having at one end brackets or supporting-arms C, in which one or more sheaves l) are journalod.

E designates the piston, which extends beyoud one end of the cylinder in the usual manner and has secured thereto bracketarms F, in which are journalcd sheaves G,

: 'orresponding iu number and size to the sheaves in the brackets C.

H is the usual carriage supporting the outvwardly-projectlug end oi' the piston, which travels upon suitahlysupportcd tracks I.

'lho cable J passes over the sheaves l) and 'fir the usual manner and over sheaves K and L and is attached at its free end tothev car M, as plainly shown in the drawing.

The parts thus brieiiy described are of the usual construction in well-known types of hydraulic elevators and constitute no part of my present invention. The counterbalancing mechanism, however, I consider asi-entirely new, and the same will now be fully described. 6o The piston is of. the hollow type, as plainly shown in the drawing, andthe head O there'- of is centrally apertured, as at P, the openingr registering with a similar opening formed in the cylinderlhead Q. A pipe R extends through the two openings and projects Within the piston, in proximity to the head X thereof, as shown, Where it is supported byahead S. This head is apertured, as at T, to receive the pipe end and to permit the latter to extend therethrough and is preferably fixedlysecured to the'pipe. The hydrostatic column constituting the counterbala'nce is contained within a Vertical pipe'U, which commu'nicates, in the manner indicated in the drawing, with the pipe R. The height of the vertical pipe is sufficient to permit of a hydrostatic pressure being exerted by the column equivalent to the Weight of the car and the weight of that port-ion of the cable be tween the car at its lowest point and the sheave L. The latter weight is generally ,termed and will be hereinafter referred to as the dead-weightA7 of the cable, which is at its maximum .when the ear is at its lowest position. i

V designates the usual water-supply pipe, which communicates with the cylinder through a suitable port in cylinder-head Q.

From the construction and arrangement of the counter-weight as set forth it will be obvious that while the piston is forced' outward from the cylinderin the usual manner bythe water-supply or any other suitable means the hyd rostatic column assists in elevatingr the car by exerting a pressure upon the head X of the piston. Also as the dead-weight of the cable diminishes during the ascension of the car the hydrostatic pr ssn re is correspondingly decreased hy lhelowering of the column.

in orderthnt the new of the water from the hydrostatic column into the hollow piston willv not interfere with the falling of the column"V below a certain point, such as A, necessary Water column sothat thehydrostatic pressure usate forl the variancein f to counteract the Weight of the car, Ienlargel the capacity of Athe vertical pipe at a certain point, Athe,enlarge'ment being designated by the letter A2. This enlargement is of the same capacity as the capacity of the piston and is formed in the pipe U above the point A3, the enlargement extendingfrom this point to the point A, the latter indicating the height vof the Water column necessary. to couuterbalance the car plus the maximum dead-weight of the cable.

The advantage of em ployin g the hydrostatic column foncounterbalancing .in place ot thel ordinary weight isthat the jumping of the car when stopped suddenly owing to the fall ofL the weight which moves at the same'velocity as thelcarvis obviated` This follows from thefact-that `the fall of the watercolumn Ais slight incomparison with the fall of the usual Weightand' the velocity is corre`- spondingly decreased: By constructing the will vary-to com-pe the dead-weight-of the cable I am enabled to dispense with the use of the compensating chains that heretofore have been found uec- 'essary 4in use.

What I claim as my invention is- In a hydraulic elevator, the combination with the ear, ot' the cable, the cylinder and a hollow piston therein for operating the cable, a pipe extending through one cylinder-head and the adjacenthead of the piston, a head attached to the pipe and arranged within the piston, and au upright pipe 'communicating with the pipe extend-ing within-said cylinder, said upwardly-extendiugpipe being provided with an enlargement equal in capacity to the capacity of the pistonisubstantially as and for the purpose described.

' In testimony whereof rl aflix myr `eigna'tture c in presence of two Witnesses. l

" Witnesses: .4,

L. J. WHrTTuMoRE H: c. sil/11TH; 

